Delivering bioabsorbable fasteners

ABSTRACT

An apparatus for delivering bioabsorbable fasteners comprises a housing and an actuator movable by a user to deliver one fastener at a time.

PRIORITY INFORMATION

This application is a continuation of U.S. patent application Ser. No.13/755,540, filed Jan. 31, 2013.

FIELD OF THE INVENTION

The invention relates to sequentially deploying a plurality ofbioabsorbable fasteners into tissue to secure two sides of an incisionor cut in the skin or other tissue of a patient.

BACKGROUND OF THE INVENTION

There are many examples of surgical staplers which deliver staples oneat a time. Most of these deliver traditional metal staples which rely onthe strength of the staple to pierce the tissue and to hold the tissuesurfaces together. Hence the typical surgical stapler engages the firststaple at the front of a linear array of staples, and pushes it into thetissue while bending it over an anvil. Once the staple is bent intoposition, the tissue surfaces that are being held cannot un-bend themetal staple. One of the disadvantages of the metal staple is that itmust have a portion that remains exposed through the skin surface inorder to allow a medical professional to remove the fastener oncebiological healing is complete. This exposed portion is unsightly, andthe puncture points where the fastener enters the skin, have a risk ofinfection.

To address the disadvantages of metal staples, various inventors haveproposed fasteners made of bioabsorbable materials which can be placedbelow the surface of the skin. This subcuticular skin closure avoidspunctures through the epidermis, and does not require follow-up removalof the staples. Such a fastener is described in U.S. Pat. No. 6,726,705to Peterson et al, as a “Mechanical Method and Apparatus for BilateralTissue Fastening”. A product based on this patent, the INSORB®Subcuticular Skin Stapler, has been commercialized by Incisive Surgicalof Plymouth, Minn. The fastener deployed by the INSORB device issignificantly thicker in cross section than a metal staple to enable theplastic material to be strong enough to maintain the traditional “U”shape of a staple during the healing process. This added bulk isundesirable as it takes longer to be absorbed by the body. Also the headof the INSORB stapler must be inserted within the incision to deploy thefastener. This means that the user has poor visibility as to theplacement of the fastener and that the device cannot be used on smallincisions such as those employed in increasingly popular minimallyinvasive surgery.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a stapler apparatus,that is easily operated by a user, to aid in the insertion of one ormore bioabsorbable fasteners for closing incisions, including smallincisions such as ones that are less than 10 mm long. Another objectiveof the present invention is to provide good visibility to the operatorof the site where the fastener will be inserted. Yet another objectiveis to provide a stapler loadable, or preloaded, with multiple fastenersstored in a magazine or cartridge, where the stapler is able to deploythe fasteners one at a time. A sufficient number of fasteners can beloaded or preloaded, or different configurations of the stapler can beprovided, to close long as well as short incisions. Another objective ofthe present invention is to provide a locking mechanism that preventsfasteners from being accidentally discharged during shipment or handlingprior to intentional use. An additional objective is to provide astapler with a safety mechanism that prevents the needles from beingexposed after the last fastener is delivered by the stapler.

The present application and invention is directed to a surgical staplingapparatus able to deploy fasteners of the type described by Danielsonet. al. in US patent application publication number 2009/0206127 A1“Tissue Fasteners and Related Insertion Devices, Mechanisms, andMethods” (hereinafter “Danielson”), which is incorporated herein byreference in its entirety. The present invention relates to a new andinnovative delivery device that is not disclosed in Danielson and thatcan be used by an operator (such as a surgeon or other medicalprofessional) to insert into tissue of a patient (such as a human orother mammal) the bioabsorbable fasteners disclosed in Danielson and toinsert them generally in accordance with the insertion procedure/stepsset forth in Danielson. Other types of bioabsorbable fasteners may alsobe used with and deployed by the disclosed apparatus.

The present invention relates to a mechanical apparatus for insertingneedles into cannulated legs of a bioabsorbable fastener. The apparatuscomprises a housing which orients and constrains other elements of theapparatus. Extending from the proximal end of the housing is an actuatorthat may be operated by the thumb of the user such that pressing theactuator into the housing causes a fastener, carried on needles andpushed by components operably connected to the actuator, to be deployedfrom the distal end of the housing. The housing further contains amagazine with a plurality of fasteners positioned on a reciprocallymovable fastener support and a timing lever, which acts on the fastenersupport to move it and release each fastener one-by-one after theneedles are inserted into the cannulated legs.

As the user continues to push the actuator, the needles and fastenerexit the distal end of the housing and deliver the fastener between thetwo sides of a bifurcated foot over which the two sides of a patient'sincision or cut have been positioned. The user has complete visibilityof the fastener as it exits the housing before it enters the tissue, andthus can adjust the position of the stapler or tissue to preciselydirect the fastener to the desired target. With manual control of speedand force, the user can deploy the fastener into the tissue such thatthe two legs of the fastener are inserted into the two sides of theincision. Upon releasing the actuator, it is returned by a spring to itsstarting position, thereby retracting the needles and leaving thefastener deployed beneath the surface of the tissue.

In order to reliably guide the needles into the cannulated legs of eachfastener, the apparatus further comprises needle guide tubes made ofcylindrical tubes which have an outside diameter similar in size to theoutside diameter of the legs of the fastener. The distal ends of theseneedle guide tubes are slideably held by shaped features at the front ofthe magazine (“huggers”) which simultaneously contact and align theneedle guide tubes and the legs of the fastener as the needles exit theneedle guide tubes and enter the fastener legs. The huggers reduce theimpact of normal manufacturing and assembly imperfections andtolerances, and allow the critical step of inserting the needles intothe cannulated legs of the fasteners to be achieved reliably, andrepeatedly, for each and every fastener loaded (or preloaded) into theapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIG. 1A shows a perspective view of the assembled apparatus of thepresent invention with safety lock installed;

FIG. 1B shows the apparatus of the present invention with safety lockremoved and actuator depressed fully to deliver a fastener;

FIG. 2A shows components of the present invention with the left housingshell 20 removed to illustrate the components inside;

FIG. 2B shows the right housing shell of FIG. 2A with all componentsremoved;

FIGS. 3A through 3D show the sequence of positions of selected parts ofthe apparatus at different steps during the deployment of a fastener;

FIG. 4 shows a partially exploded perspective view of the magazine andcap and selected components normally assembled together;

FIG. 5 shows a cross section of the magazine and cap taken along theA-A′ plane of FIG. 4 and including non-sectioned views of some internalcomponents;

FIG. 6A shows a perspective view of the fastener support with thefront-most fastener and guide tube support with needle guide tubes andtiming lever positioned at the start of delivery of a fastener;

FIG. 6B shows the same perspective as FIG. 6A with the componentspositioned at an intermediate point in the delivery of the front-mostfastener; and

FIG. 7 shows a cross section of the components of FIG. 4 taken along theB-B′ plane, positioned at the start of delivery of a fastener as shownin FIG. 6A.

DETAILED DESCRIPTION

FIG. 1A illustrates a perspective view of an apparatus 10 for insertingbioabsorbable fasteners to secure the two sides of an incision in tissueas illustrated in FIG. 1 and FIG. 2 of Danielson (US patent applicationpublication number 2009/0206127 A1). For purposes of this descriptionthe proximal end, the end closest to the operator, is at the top of thefigure and the distal end, the direction away from the operator, is atthe bottom of the figure. FIG. 1A shows the apparatus as it may bepresented to the user, preloaded with fasteners and secured withactuator lock 13, which serves as a safety to prevent the fasteners frombeing accidentally discharged during shipment or handling prior to theirintentional use. Actuator lock 13 may be fabricated from a flexibleplastic such as polypropylene by molding or die-cutting, for example,from sheet material approximately 0.030″ thick.

Now with reference to FIGS. 1A and 1B, the apparatus 10 comprises a lefthousing shell 20 and a right housing shell 30 which are assembledtogether to form a housing 25 which orients and constrains otherelements of the apparatus. Extending from the proximal end of thehousing 25 is an actuator 40 that may be operated by the thumb of theuser. As illustrated in FIG. 1B, removing the actuator lock 13 andpressing the actuator thumb pad 43, causes actuator 40 to move into thehousing 25. Guiding surfaces and components described below operatewithin the housing 25 such that a fastener 50 is delivered through theopening in the distal end of the housing 25. The fastener is carried onneedles, and guided by guide tube support 73, to move along a linecentered between the left foot 22 and right foot 32, over which the twosides of the tissue (see FIG. 12a of Danielson) have been positioned. Asillustrated in FIG. 12b of Danielson, the two legs of fastener 50penetrate the two sides of the cut tissue (see 68a and 68b ofDanielson). After inserting the fastener 50 into the tissue, the userreleases pressure on actuator thumb pad 43, and a spring returnsactuator 40 to the starting position. As the needles retract, thefastener 50 remains in the tissue as illustrated in FIG. 12c ofDanielson. Finally as illustrated in FIG. 12d of Danielson, the barbs ofthe fastener engage, and the cut surfaces (68a and 68b of Danielson)return in anatomical apposition with one another.

Now the various components of the apparatus 10 will be identified withreference to FIGS. 2A and 2B. FIG. 2A shows the components of thepresent invention with the left housing shell 20 removed to illustratethe components inside. FIG. 2B shows the right housing shell 30 alone,so that features that are obscured by the components in FIG. 2A, can beidentified more easily. When components are symmetrical, the numberedfeatures will be labeled with “a” for the left side and “b” for theright side, but in the text these symmetrical elements will beidentified as “a,b”, even if only one component is visible in aparticular drawing.

Now turning to FIG. 2A, the actuator 40 is shown in the “up” or startingposition, which is maintained by actuator return spring 45. The travelof actuator 40 is guided by actuator tongues 47 a,b, which slide inactuator grooves 53 a,b (see FIG. 2B). A resilient arm extending fromthe actuator 40, forms trigger 55, which is constrained to move in camtrack 61 (see FIG. 2B). At the distal end of the actuator 40 needles 65a,b are rigidly fixed in place. The needles 65 a,b are, in oneembodiment of the apparatus 10, made from surgical grade stainless steeland secured to actuator 40 by adhesive bonding or by being over-moldedwith actuator 40 by injection molding practices known in the art.

Needles 65 a,b are long and extend distally through the entire length ofneedle guide tubes 67 a,b. The needle guide tubes 67 a,b are rigidlyattached to guide tube support 73. The travel of the guide tube support73 is guided by guide tongues 59 a,b which slide in guide grooves 82 a,b(see FIG. 2B). The upward motion of the guide tube support 73 is limitedby guide stops 85 a,b (see FIG. 2B), which block the travel byinterfering with the proximal end of guide tongues 59 a,b.

The actuator 40 is able to push and pull the guide tube support 73, butdoes so indirectly by making contact with different surfaces atdifferent times, as will be described below. A frictional engagement isprovided by detent-protrusion 91 on guide tube support 73, whichcontacts a detent-receiver 93 on actuator 40. As the user continues topress on actuator thumb pad 43, the actuator moves and contact surface105 on the actuator comes into contact with push-pull tab 107 on theguide tube support 73. This allows force to be transferred to needleguide tubes 67 a,b to push the fastener into the tissue, as will beexplained with reference to FIGS. 3A-3D. Actuator 40 also has anactuator stop protrusion 120, which extends outward from the axis of theactuator in order to contact the stop surface 225 on the top of themagazine 200. This interference limits the distal motion of the actuator40, and hence the depth that the fastener is inserted into the tissue.After the fastener has been deployed, the actuator 40 is able to pullguide-tube support 73 when the proximal end of detent receiver 93engages the push-pull tab 107, the position illustrated in FIG. 2A.Finally actuator 40 has lock receiver notches 127 a,b, which allowactuator lock 13 (see FIG. 1A) to be inserted. When actuator lock 13 isinserted into actuator notches 127 a,b, downward motion of actuator 40is blocked.

Continuing with reference to FIG. 2A, a timing lever 150 is shown in the“up” or starting position, which is maintained by timing lever spring155. The timing lever 150 has a proximal portion which includes timinglever slot 159 which slidably contacts timing lever tab 175 on righthousing shell 30 (see FIG. 2B) to guide and limit the travel of thetiming lever 150. Also, at the proximal end of timing lever 150, thereis a trigger engagement surface 180, which is the proximal facingsurface of a feature that protrudes from the part in order to providemomentary contact with trigger 55 on the actuator 40. The distal portionof timing lever 150 is split into two legs 160 a and 160 b. The distalends of legs 160 a,b have retractor contours 165 a,b respectively, whichwill be described in more detail with the description of the timingsequence of FIGS. 3A-3D.

Finally shown in FIG. 2A is a magazine cap 215, which assembles togetherwith magazine 200, to form an enclosure that contains a plurality offasteners and other components that will be described with reference toFIG. 5. In an exemplary embodiment, magazine 200 and cap 215 arefabricated by injection molding processes from a plastic material suchas Nylon 66 (for example natural Zytel® 103 available from E.I. DuPontde Nemours & Co. of Wilmington, Del.). The magazine 200 is loosely heldin position within housing 25 by magazine tabs 205 a,b (see FIG. 4),which extend through magazine slots 207 a,b (see FIG. 2B).

The present invention will be better understood from a description ofthe different actions involved in deploying a fastener. The differentsteps are illustrated in FIGS. 3A-3D but the description will rely alsoon references to FIGS. 2, 5, 6A, and 6B. In FIG. 3A, the guide tubesupport 73, the actuator 40, and the timing lever 150 are all in theirmost proximal (up) position. At this, the starting point, the needles 65a,b are retracted such that their distal ends do not extend beyond thedistal ends of the needle guide tubes 67 a,b. This position, asillustrated in FIG. 2A, places distal ends of needles 65 a,b 1 mm to 2mm above the top of the front-most fastener 50 a. When the user firstpushes the actuator 40, the frictional engagement of detent-protrusion91 on guide tube support 73 with detent-receiver 93 on actuator 40causes the guide tube support 73 to move downward together with theactuator 40.

FIG. 3B illustrates the position of the same components as shown in FIG.3A after the actuator 40 and guide tube support 73 have moved 1 mm to 2mm, and the distal ends of the needle guide tubes 67 a,b have madecontact with the top of the front-most fastener 50 a. At this point thefastener is still supported by the fastener support 270, and cannot movedownward. This interference causes the detent-protrusion 91 to disengagefrom the detent-receiver 93, so that the actuator 40 can continue movingdownward, while the needle guide tubes 67 a,b temporarily remainmotionless. An additional 1 mm to 2 mm of movement of actuator 40, whichoccurs after the position shown in FIG. 3B, allows the sharp distal endof each of the needles 65 a,b to protrude from the distal end opening ofthe needle guide tube 67 a,b, and begin to enter the cannulated legs ofthe fastener (described later with reference to FIGS. 6A and 6B).

In FIG. 3C, the actuator 40 has moved distally bringing trigger 55 intocontact with the timing engagement surface 180 of the timing lever 150.This movement of actuator 40 also moves needles 65 a,b, which aremechanically fixed to the actuator 40, to fully insert the needles intothe cannulated legs of the front-most fastener 50 a (see FIG. 6B). Theinterference between trigger 55 and timing engagement surface 180, movestiming lever 150 downward, causing the retractor contours 165 a,b of thetiming legs 160 a,b to move fastener support 270 rearward. Asillustrated in FIG. 3C, movement of the fastener support 270 leaves thefront-most fastener 50 a without support, held only by the frictionalcontact with needles 65 a,b.

In FIG. 3D, the actuator 40 has been pushed further downward, andcontact surface 105 has pressed against push-pull tab 107, causing theguide tube support 73 to push the front-most fastener 50 a from themagazine and deliver it to the tissue (see FIG. 12b of Danielson—USPatent application publication number 2009/0206127 A1). At the sametime, cam track 61 (see FIG. 2B) has caused trigger 55 to lose contactwith trigger engagement surface 180 of the timing lever. As the contactis lost timing lever 150 returns to its up position, forced by timinglever spring 155. This is the position shown in FIG. 3D. Once the timinglever 150 has returned, fastener support 270 is urged forward byfastener support spring 287 (see FIG. 5). However, the actual return offastener support 270 to its initial forward position, is not possibleuntil the needle guide tubes 67 a,b move up out of the way. This happenswhen the user releases pressure on actuator thumb pad 43, and returnspring 45 pulls the actuator 40 upward. When actuator 40 moves upwards,the needles retract inside the needle guide tubes 67 a,b, and theproximal surface of detent receiver 93 engages push-pull tab 107, topull guide tube support 73 and needle guide tubes 67 a,b upward to thestarting position shown in FIG. 3A.

FIG. 4 shows the magazine 200 removed from the apparatus anddis-assembled from cap 215. The cap 215 may be secured to the body ofthe magazine by various means known in the art such as adhesive bondingor ultrasonically welding. In one embodiment illustrated in FIG. 4, areleasable attachment is provided by cap latches 260 a,a′,b,b′ on themagazine 200, which have a barbed shape at the end of a flexible arm.During assembly the flexible arms bend slightly to allow the cap latches260 a,a′,b,b′ to be inserted through openings in cap 215. Once fullyinserted, the flexible arms straighten to their original shape, and thecap latches 260 a,a′,b,b′ secure the cap by pressing against latch seats263 a,a′,b,b′ respectively. At the top of cap 215 there is a timinglever spring tab 222 which registers the distal end of the timing leverspring 155 to hold it in place.

Continuing with reference to FIG. 4, at the top of the magazine 200there is a stop surface 225 which stops the distal motion of theactuator 40 by interfering with the actuator stop protrusion 120 (seeFIG. 2A). Huggers 210 a,a′,b,b′ extend from the front of the magazine200 where they provide a sliding contact with the needle guide tubes 67a,b (see FIG. 7). The magazine 200 also has timing leg support surfaces230 a,b that provide surfaces along which the distal end of timing legs160 a,b (see FIG. 6A, 6B) may slide. This allows timing lever 150 to beonly loosely guided in its motion by timing lever tab 175 (see FIG. 2b), which slides in timing lever slot 159 (see FIG. 2A). The criticalreference geometry for timing lever 150 is provided by a sliding contactbetween timing legs 160 a,b (see FIG. 2A) and timing leg supportsurfaces 230 a,b.

FIG. 5 shows a cross section of the magazine 200 and cap 215 assembledtogether and taken along the A-A′ plane of FIG. 4. The left side of FIG.5, referred to as the front of magazine 200, shows the guide tubesupport 73 and needle guide tube 67 a positioned against huggers 210 band 210 b′. Within the magazine 200 are ten (10) fasteners 50 a through50 j positioned on the fastener support 270. The front-most fastener 50a is in close contact with hugger 210 b′, and therefore positioneddirectly in alignment with needle guide tube 67 a. Contact of thefront-most fastener 50 a with the huggers is assured due to contact withthe remaining fasteners 50 b-j which is urged forward by pusher 275 andpusher spring 277. In an exemplary embodiment, pusher 275 is fabricatedby injection molding processes from a plastic material such as Nylon 66(for example Zytel® 101L available from E.I. DuPont de Nemours & Co. ofWilmington, Del.) with smooth sliding surfaces facing the fastenersupport 270. Pusher spring 277 is a compression spring fabricated from,for example, Type-302 stainless steel. Pusher spring 277 is held inplace by pusher spring tab 283, located on the pusher, and upper springtab 285, located on the cap 215. Travel of the pusher 275 is guided bypusher tongues 280 a,b which travel in pusher grooves 250 a,b (see FIG.4).

The exemplary embodiment of the present invention shown in FIG. 5includes ten (10) fasteners 50 a-j, but it will be understood by thoseskilled in the art that simple changes in dimensions of the componentscan be made to accommodate a smaller or larger number of fasteners inthe assembly. A number of fasteners in the range of 1 to 25 iscontemplated by the present invention in order to provide a sufficientnumber to close both short and long incisions.

Continuing with reference to FIG. 5, after one of the fasteners 50 a-jis inserted into the tissue, the needle guide tubes move proximally toclear the way for fastener support 270 to move forward (returning to theposition illustrated in in this FIG. 5 and in FIG. 3A). Once needleguide tubes 67 a,b move proximally out of the way, pusher 275 is urgedforward by pusher spring 277 to advance all remaining fasteners therebybringing the next fastener (for example, 50 b) into the front-mostposition.

When all fasteners have been deployed, a safety mechanism is introducedthat prevents the needles 65 a,b from being extended again. This isaccomplished by pusher stop surface 286 which is the front-most portionof pusher 275. After the last fastener is delivered and the needle guidetubes 67 a,b move up and out of the way, pusher 275 moves forward (leftin FIG. 5) urged by pusher spring 277, to position pusher stop surface286 directly below the needle guide tubes 67 a,b. If the user presses onthe actuator 40 in this condition the guide tubes are blocked frommoving downward and the needles remain with the housing 25.

Continuing with reference to FIG. 5, the fasteners 50 a-j are positionedon fastener support 270 which is urged toward the front of the magazineby fastener support spring 287. Fastener support 270 may be fabricatedby injection molding processes using a material such as Food GradeNatural Acrylonitrile Butadiene Styrene (“ABS”) (e.g. Lustran 433-000000which is available from INEOS ABS Corporation of Addyston, Ohio).Fastener support spring 287 is a compression spring fabricated from, forexample, Type-302 stainless steel. It is held in place by fastenersupport spring tab 293, located on the fastener support 270, and lowerspring tab 297, located on the cap 215. Travel of the fastener supportis guided by fastener support tongues 295 a,b which travel in fastenersupport grooves 240 a,b (see FIG. 4). As will be described below, thetravel of the fastener support 270 reciprocates (left and right in FIG.5) over a very short distance. In an alternate embodiment, the fastenersupport spring 287 could be replaced by a simple resilient arm. In suchan embodiment, the resilient arm, having an effective spring rate ofapproximately 1 lb/inch, is molded as part of one of the contactingparts, the magazine 200, the fastener support 270 or the cap 215, toprovide the necessary restoring force to move the fastener support 270.

FIGS. 6A and 6B show the fastener support 270 together with thefront-most fastener 50 a, guide tube support 73, needle guide tubes 67a,b and the distal portion of timing legs 160 a,b, to illustratedetailed features of these parts. The fastener 50 a is the type offastener described by Danielson (US patent application publicationnumber 2009/0206127 A1) and made from bioabsorbable materials. It isshown having a bridge 313 connecting two cannulated legs 317 a and 317 beach with barbs 333 a and 333 b respectively. The cannulated legs 317a,b have openings 325 a,b that are chamfered at the top of legs 317 a,b.The chamfer provides a slightly larger diameter for openings 325 a,b tofacilitate insertion of needles 65 a,b respectively. The fastenersupport 270 has a ridge 340 on which the bridge 313 of the fastenerrests. Below the ridge 340, the cross-sectional shape of the fastenersupport 270 is designed to match features of the fasteners. Inparticular, sidebars 305 a,b run the full length of the fastener support270 and are shaped to restrain the barbs 333 a,b of the fasteners frombeing easily dislodged upward. Thus the fasteners are able to slide in alinear fashion along the length of ridge 340 of the fastener support 270arriving at the front-most position with a predictable position asillustrated.

Continuing with reference to FIG. 6A, the fastener support tongues 295a,b are interrupted at the rear by notches 345 a,b which engage timinglever legs 160 a,b. The front-most fastener 50 a is positioned directlybelow the needle guide tubes 67 a,b and aligned with the needles 65 a,b(retracted within the tubes) because both are in slidable contact withthe huggers 210 a,a′,b,b′ (see FIG. 5). Timing leg 160 a is shown withthe distal end positioned in notch 345 a of the fastener support. Therearward edge of notch 345 a is in direct contact with retractor contour165 a due to the urging of fastener support spring 287 (see FIG. 5).

In FIG. 6B the same components as illustrated in FIG. 6A are shown in aposition previously described with reference to FIG. 3C. Downwardmovement “A” advances the needles 65 a,b inserting them into thecannulated legs 317 a,b of the front-most fastener 50 a. Simultaneouslythe downward movement “B” of timing legs 160 a,b causes retractorcontours 165 a,b to press against notches 345 a,b to move the fastenersupport 270, as illustrated by arrow “C”, away from the front-mostfastener 50 a. This action, taken immediately after the needles 65 a,bare inserted into the fastener, leaves front-most fastener 50 a withoutsupport from the fastener support 270. Without support from the fastenersupport 270, the front-most fastener 50 a is supported only byfrictional contact with needles 65 a,b, and can be pushed by needleguide tubes 67 a,b to move distally out of the magazine 200.

Needles 65 a,b are made from surgical grade stainless steel or othersimilarly strong material(s) and sharpened with a conical point by meansfamiliar to those in the art. The needle guide tubes 67 a,b are madefrom stainless steel and have an external surface that is similar inshape and size to the external surface of the fastener legs 317 a,b.Other material(s) can be used to make the needle guide tubes 67 a,b. Ina preferred embodiment, the needle guide tubes 67 a,b and fastener legs317 a,b are cylindrical in shape and have the same outside diameter. Theneedle guide tubes 67 a,b are spaced apart by a distance equal to thedistance separating fastener legs 317 a and 317 b from one another. Theneedle guide tubes 67 a,b are rigidly fixed to the guide tube support 73by means known in the art. In one embodiment, the guide tube support 73is made by injection molding using a material such as AcrylonitrileButadiene Styrene (ABS) or acrylics (for example, Cyrolite® acrylicbased compounds available from Cryo Industries, Rockaway, N.J.). Theneedle guide tubes 67 a,b may be separately fabricated with aspacer-attachment structure to hold them parallel to each other. theneedle guide tubes 67 a,b with such an attachment structure may beattached to guide tube support 73 by means know in the art such asscrews, thermo-staking, or adhesive bonding. The stainless steel needleguide tubes 67 a,b may also be insert molded to be part of guide tubesupport 73 as a molded part.

FIG. 7 shows a cross section of the components of FIG. 4 taken along theB-B′ plane with the selected components positioned as previouslyillustrated in FIGS. 3A and 6A. The front-most fastener 50 a is shownpositioned on fastener support 270 directly below the needle guide tubes67 a,b. The legs 317 a and 317 b of the front-most fastener 50 a are inslidable contact with the huggers 210 a′ and 210 b′ respectively.Similarly the needle guide tubes 67 a,b are in slidable contact withhuggers 210 a,a′,b,b′. The needles 65 a,b are constrained to move withinthe needle guide tubes 67 a,b which causes them to be axially alignedwith openings 325 a,b. By the sequence described with reference to FIGS.3A-3D, the needle guide tubes 67 a,b move downward to contact the top oflegs 317 a,b and then the needles 65 a,b advance from within the needleguide tubes to enter openings 325 a,b.

FIG. 7. illustrates the most demanding functionality of the presentinvention; that is, introducing the distal points of needles 65 a,b intothe openings 325 a,b at the top of the fastener legs 317 a,brespectively. This is accomplished without impossibly tightmanufacturing processes by registering the critical parts and placingthem into sliding contact with one another. This contact is created bythe features on the magazine 200 called huggers 210 a,a′,b,b′. Byadapting the needle guide tubes 67 a,b and fastener legs 317 a,b to havethe same shape (e.g. cylindrical) and to have the same cross-sectionaldimensions (e.g. outside diameter), both parts can be urged into contactwith a common surface. In one embodiment, illustrated in FIG. 7, huggers210 a,a′,b,b′ are in sliding contact with needle guide tubes 67 a,b andfront-most fastener 50 a, which places the needles 65 a,b in axialalignment with the openings 325 a,b. Because the magazine 200 is free tomove within the magazine slots 207 a,b (see FIG. 2B) it is able toremain referenced to the needle guide tubes 67 a,b due to the slidingcontact of the huggers 210 a,a′,b,b′.

The apparatus of the present invention has been described with referenceto ten (10) bioabsorbable fasteners of the type described by Danielson(US patent application publication number 2009/0206127 A1). Thoseskilled in the art will realize that the benefits of the invention maybe applied to other fasteners, whether made from bioabsorbable materialsor not. Realizing that the objective is to deliver fasteners one at atime from a cartridge having a multiplicity of fasteners, it will beapparent that the apparatus may be adapted by obvious modifications todeliver fasteners in greater or lesser number than ten. Alternateembodiments also can work with fasteners having a greater or lessernumber of legs than two. Fasteners that do not have cannulated legs canbenefit from the present invention if such fasteners are adapted to havefeatures such as holes or slots into which guiding elements, for exampleneedles, may be inserted. While the present invention has been set forthin terms of a specific embodiment or embodiments, it will be understoodthat the present invention herein disclosed may be modified or alteredto other configurations. Accordingly, the invention is not limited onlyto disclosed details.

1. Apparatus for delivering bioabsorbable fasteners that each includes afirst leg and a second leg, the apparatus comprising: a housingconfigured to be held by a hand of a user, the housing having a proximalend, a distal end, and a length; an actuator extending out of theproximal end of the housing and configured to be moved by the user alongthe length of the housing and at least partially into the housing; apair of needles operably connected to the actuator; an alignment surfaceconfigured to axially align at least one of the needles with at leastone of the first and second legs of the fastener; a magazine comprisinga plurality of the fasteners and a pusher configured to urge one of theplurality of fasteners at a time into contact with the alignmentsurface; needle guides configured to slideably guide the needles whenthe actuator is moved by the user to allow the needles to engage thefirst and second legs of the fastener, the needles and the engagedfastener exiting the distal end of the housing when the user moves theactuator; and a fastener support configured to move as a result of theactuator being moved by the user, movement of the fastener supportreleasing from the magazine the one fastener that is engaged with theneedles and in contact with the alignment surface.
 2. The apparatus ofclaim 1 further comprising a locking mechanism that prevents thefastener from exiting the distal end of the housing prior to usermanipulation of the locking mechanism.
 3. The apparatus of claim 1further comprising a safety mechanism that prevents the needles frombeing exposed out of the distal end of the housing after all of theplurality of the fasteners have exited the distal end of the housing. 4.The apparatus of claim 1 further comprising a spring operativelyconnected to the actuator and configured to be deformed when the usermoves the actuator at least partially into the housing and to providerestoring force to return the actuator to a starting position when theuser releases pressure on the actuator.
 5. Apparatus for delivering abioabsorbable fastener into two sides of an incision or cut in skintissue, the apparatus comprising: a housing having a proximal end and adistal end, the housing adapted to be held in the hand of a user; afirst foot and a second foot extending from the distal end of thehousing and configured so that each of the two sides of the incision orcut is positioned over a foot; an actuator extending from the proximalend of the housing and configured to be moved by the user along a lengthof the actuator, into the housing, and at a speed controlled by theuser; and at least one needle operatively connected to the actuator andadapted to releasably engage the fastener and to exit the distal end ofthe housing to deliver the fastener between the first foot and thesecond foot when the user moves the actuator such that a portion of thefastener is inserted into each of the two sides of the incision or cut.6. The apparatus of claim 5 further comprising an actuator thumb padlocated at the proximal end of the actuator and whereby movement of theactuator into the housing results when pressure is applied to theactuator thumb pad by a thumb of the user.
 7. The apparatus of claim 6further comprising a spring operatively connected to the actuator andconfigured to be deformed when the user moves the actuator into thehousing and to provide restoring force to return the actuator to astarting position when the user releases pressure on the actuator thumbpad thereby retracting the needles and leaving the fastener deployed inthe two sides of the incision or cut in the skin tissue.
 8. Theapparatus of claim 5 wherein the bioabsorbable fastener comprises afirst leg and a second leg configured such that the first leg is theportion of the fastener inserted into one of the two sides of theincision or cut and the second leg is the portion of the fastenerinserted into the other side of the incision or cut.
 9. Apparatus fordelivering a bioabsorbable fastener into two sides of an incision or cutin skin tissue, the apparatus comprising: a housing having a proximalend and a distal end, the housing adapted to be held in the hand of auser; an actuator extending from the proximal end of the housing andconfigured to be moved into the housing by the user of the apparatusalong a length of the actuator; a pair of needles operably connected tothe actuator and adapted to slideably engage the bioabsorbable fastenerand to exit the distal end of the housing to deliver the fastener suchthat a portion of the fastener is inserted into each of the two sides ofthe incision or cut; and a spring operatively connected to the actuatorand configured to be deformed when the user moves the actuator into thehousing and to provide restoring force to return the actuator to astarting position when the user releases pressure on the actuatorthereby retracting the needles and leaving the fastener deployed in theskin tissue.
 10. The apparatus of claim 9 further comprising a pluralityof the fasteners positioned in contact with each other and a pusherconfigured to urge the plurality of fasteners such that, after onefastener exits the distal end of the housing and the actuator returns tothe starting position, another fastener is positioned to be deliveredwhen the user operates the apparatus.
 11. The apparatus of claim 9wherein the bioabsorbable fastener is one of a plurality of fastenersdelivered one at a time when the user moves the actuator into thehousing and the spring returns the actuator to the starting position.